How to use DecimalFormat in Java?

DecimalFormat can be used to format numbers with patterns like ###,###.###.

Here's how you can use it:

var formatter = new DecimalFormat("###,###.###");

System.out.println(formatter.format(123456789.1234)); // 123,456,789.123
System.out.println(formatter.format(0.1234)); // 0.123